When thousands of visitors come to Minneapolis for the All-Star baseball game in July, downtown Minneapolis will be designated a "clean zone," but not because they are closing down the strip joints or giving the streets a little more elbow grease.

The city has made an agreement with Major League Baseball to prohibit such nefarious activities as "block events, parades, races, billboard vehicles, inflatable displays and product sampling."

But Chuck Samuelson, executive director of the American Civil Liberties Union of Minnesota, said the language doesn't just apply to commercial ventures, it could also serve to inhibit free speech in a large section of the city for the two weeks surrounding the game. Anyone wanting to protest or demonstrate needs the approval of MLB, he said.

"The city can't give away property or speech rights to a for-profit company," said Samuelson. "The government has to follow the Constitution. Major League Baseball doesn't."

The ACLU-MN submitted a letter to the City Council objecting to the wording of the agreement, but the council passed it anyway. In the letter, the ACLU-MN warns that the city "would be opening itself up to legal liability for First Amendment violations."

Sounds to me like a lawsuit threat. I asked Samuelson if there was one pending, and he got coy. He repeatedly, though good-naturedly, dodged my question.

In other words, don't be surprised to see a lawsuit.

I asked Samuelson who might be a potential litigant in such a suit.

Hypothetically.

"Anybody who lives downtown who wants to put a sign in their window or sell lemonade" during the clean-zone blackout, Samuelson said.

Matt Hoy, All-Star Game coordinator for the Twins, called the ACLU's response "a gross overreaction" to the agreement.

"Every national event, whether it be a Super Bowl or Final Four, every city has a similar agreement," said Hoy, who said he didn't think the wording would allow MLB to hinder any political speech.

"Not in my estimation, but everybody has their own interpretation," said Hoy.

He said other events, such as the Basilica Block Party, are being held with no objection from baseball. He said that the agreement was worded broadly, but that it was meant to protect against, say, businesses wrapping their buildings with banners of competing sponsors.

Council Member Blong Yang said he got the ACLU letter right before the vote and after the issue had already passed through committees. Yang is a lawyer and doesn't think the agreement with MLB would stop anyone from expressing their free speech.

"We've had clean zones in the past, and there were no problems," said Yang. "We had them for the Twins playoffs and World Series games, though I think this zone is bigger than before."

Yang's view is that "the U.S. Constitution trumps anything" in the agreement, and he added that he would side with the ACLU if the league tried to prohibit anyone's political speech.

The agreement is obviously an attempt to keep citizens and businesses from siphoning profits away from the game and the league. But the clean zone won't just exist on game day, July 15: It extends from July 5 to July 20, and it includes all of downtown, part of northeast Minneapolis and areas around the University of Minnesota.

The agreement states that the city established a clean zone "around Target Field during the 2014 Major League Baseball All-Star Game and related events, where temporary sales, vending, entertainment, signs and related special event permits will not be approved or issued by the City of Minneapolis without the additional approval of Major League Baseball."

Asked if the arrangement could set a precedent for, say, a likely NFL Super Bowl at the new Vikings stadium, Samuelson said, "absolutely."

That could mean that American Indians wouldn't be allowed anywhere close to the stadium if they wanted to protest the name of the Washington Redskins, as they have done in the past, Samuelson said.

Hoy disagrees.

"Major League Baseball's interest is not to limit free speech or commerce," said Hoy. "It's in our interests for all businesses to reap the benefits of the game, not constrain them. We're trying to showcase the city."

jtevlin@startribune.com • 612-673-1702 Follow Jon on Twitter: @jontevlin